C-2-Symmetric (SO)N(SO) Suloxide Pincer Complexes of Mg and Pd: Helicity Switch by Ambidentate S/O-Coordination and Isolation of a Chiral Pd-Sulfenate

Seidel F, Frieß S, Heinemann FW, Chelouan A, Scheurer A, Grasruck A, Herrera AC, Dorta R (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Organometallics American Chemical Society

Book Volume: 37

Pages Range: 1160-1171

DOI: 10.1021/acs.organomet.8b00038

Abstract

Quinine-based (R)-tert-butylsulfinate 3 reacts with tris-lithiated bis-arylamide 2 to afford gram-quantities of optically pure (S*O)N(S*O) sulfoxide pincer ligand (R,R)-4. Deprotonation of (R,R)-4 and p-Tol-substituted analogue (S,S)-5 with MgPh2 and BnK yields respective Mg and K amido-bis-sulfoxides 6–9. In Mg complexes 6 and 7, the sulfoxide functions are O-coordinated, thereby imparting a pronounced helicity to the ligand backbone. Transmetalation of 6 and 7 with [PdCl2(NCPh)2] affords the S,S-coordinated C2-symmetric and the O,S-coordinated C1-symmetric chlorido complexes 10 and 11, respectively, and reaction of potassium amides 8 and 9 with [PdCl(CH3)(COD)] leads to methyl-palladium pincer complexes 12 and 13, respectively. The crystal structures of 6, 7, 12, and 13 reveal a chameleonic ligand system with predictable behavior: (R)-configured 4 induces pronounced λ backbone helicity in the O-coordinated Mg-complex and weaker δ helicity in S-coordinated Pd-complexes, while (S)-configured ligand 5 mirrors this stereochemistry. S-Coordination induces stronger, C2-symmetric, steric crowding in the head-on quadrants compared to O-coordination. When (R,R)-4 is reacted with 2 equiv of [Pd(CH3)2(tmeda)], crystalline chiral Pd-sulfenate complex 16 forms by elimination of iso-butene and methane with inversion of configuration at the sulfenate S atom.

Authors with CRIS profile

Falk Seidel Lehrstuhl für Anorganische und Allgemeine Chemie Sibylle Frieß Professur für Anorganische Chemie Frank Wilhelm Heinemann Lehrstuhl für Anorganische und Allgemeine Chemie Ahmed Chelouan Lehrstuhl für Anorganische und Allgemeine Chemie Andreas Scheurer Lehrstuhl für Anorganische und Allgemeine Chemie Alexander Grasruck Professur für Anorganische Chemie Alberto Cesar Herrera Professur für Anorganische Chemie Romano Dorta Professur für Anorganische Chemie

How to cite

APA:

Seidel, F., Frieß, S., Heinemann, F.W., Chelouan, A., Scheurer, A., Grasruck, A.,... Dorta, R. (2018). C-2-Symmetric (SO)N(SO) Suloxide Pincer Complexes of Mg and Pd: Helicity Switch by Ambidentate S/O-Coordination and Isolation of a Chiral Pd-Sulfenate. Organometallics, 37, 1160-1171. https://dx.doi.org/10.1021/acs.organomet.8b00038

MLA:

Seidel, Falk, et al. "C-2-Symmetric (SO)N(SO) Suloxide Pincer Complexes of Mg and Pd: Helicity Switch by Ambidentate S/O-Coordination and Isolation of a Chiral Pd-Sulfenate." Organometallics 37 (2018): 1160-1171.

BibTeX: Download